A smokejumper is a specially-trained wildland firefighter who provides an initial attack response on remote wildfires. They are inserted at the site of the fire by parachute. This allows firefighters to access remote fires in their early stages without needing to hike long distances carrying equipment and supplies. Traditional terrestrial crews can use only what they can carry and often require hours and days to reach fire on foot. The benefits of smokejumping include the speed at which firefighters can reach a burn site, the broad range of fires a single crew can reach by aircraft, and the larger equipment payloads that can be delivered to a fire compared to pedestrian crews.

Once arrived on site, smokejumpers use similar strategies to hotshot crews and terrestrial crews to extinguish fires. Primarily, firefighters use axes to dig trenches around the fire's perimeter to isolate the flames from further fuel sources - nearby trees and shrubs. By tilling the newly exposed soil, the firefighters limit available material for the fire and it slowly burns itself out. If necessary, crews will supervise the fire overnight, and churn the ash in the morning to effectively put out any remaining embers. Once the fires are deemed thoroughly extinguished, smokejumpers retrieve the equipment and hike to the nearest clearing to be collected by helicopter.

As of 2025, there are only five countries that currently house smokejumpers: Russia, China, Canada, United States and Malaysia. These countries often coordinate exchange programs in which smokejumpers travel to aid in intense wildfire seasons.

In addition to performing the initial attack on wildfires, they may also provide leadership for extended attacks on wildland fires. Shortly after smokejumpers touch ground, they are supplied by parachute with food, water, and firefighting tools, making them self-sufficient for 48 hours. Smokejumpers are usually on duty from early spring through late fall.

Prior to the full establishment of smokejumping, experiments with parachute insertion of firefighters were conducted in 1934 in Utah and in the Soviet Union. Earlier, aerial firefighting experiments had been conducted with air delivery of equipment and water bombs. Although this first experiment was not pursued, another began in 1939 in the Methow Valley, Washington, where professional parachutists jumped into a variety of timbered and mountainous terrains, proving the feasibility of the idea.

Smokejumping was first proposed in 1934 in the Intermountain Region (Region 4), by Regional Forester T.V. Pearson. By 1939, the program began as an experiment in the Pacific Northwest Region (Region 6). The first official non-fire jump was made in the Nez Perce National Forest in the Northern Region (Region 1) in 1940 by John Furgurson and Lester Gohler. The McCall smokejumper program was established in 1943; their base is on the Idaho shores of Payette Lake. The base is near six national forests: Nez Perce / Clearwater, Sawtooth, the Boise, Payette, Salmon–Challis, and Wallowa-Whitman.

In 1942, permanent jump operations were established at Winthrop, Washington, and Ninemile Camp, an abandoned Civilian Conservation Corps camp (Camp Menard) a mile north of the Forest Service's Ninemile Remount Depot (pack mule) at Huson, Montana, about 30 mi (48 km) northwest of Missoula. The first fire jumps were made by Rufus Robinson and Earl Cooley at Rock Pillar near Marten Creek in the Nez Perce National Forest on July 12, 1940, out of Ninemile, followed shortly by a two-man fire jump out of Winthrop. In subsequent years, the Ninemile Camp operation moved to Missoula, where it became the Missoula Smokejumper Base. The Winthrop operation remained at its original location, as North Cascades Smokejumper Base. The "birthplace" of smokejumping continues to be debated between these two bases, the argument having persisted for about 70 years.

The first smokejumper training camp was at the Seeley Lake Ranger Station, over 60 mi (97 km) northeast of Missoula. The camp relocated to Camp Menard in July 1943. Here, when not fighting fires, the men spent much time putting up hay to feed the hundreds of pack mules that carried supplies and equipment to guard stations and fire locations. To work fires, the men, organized into squads of eight to fifteen, were stationed at six strategic points, also known as "spike camps": Seeley Lake, Big Prairie, and Ninemile in Montana; Moose Creek and McCall in Idaho; and Redwood Ranger Station in southwestern Oregon at the edge of Cave Junction. The men worked from other spike camps as well, including some in Washington.